The present invention relates to an image scanner with one lighting unit and one drive system for scanning either reflective or transparent objects, and particularly to an image scanner that may scan either reflective or transparent objects by using the same lighting unit and drive system.
Generally speaking, there are two different modes for scanning reflective and transparent objects with the platform image scanner, and up to now different units have been used for the two different modes of scanning.
The majority of image scanners are mainly designed for scanning reflective objects. The action of said mode, referring to FIG. 1, is to use a clamping plate 1 and a glass plate 2 for holding the object 3 in position on the scanning plane of the scanner with the side of the object 3 to be scanned facing said glass plate 2. On the scanning side facing said object 3 there is a lighting unit 4a and a mirror unit 5; said lighting unit is provided for projecting light to image sensor 6 of said image scanner. Said lighting unit 4a, mirror unit 5 and image sensor are driven by a drive system(not shown) for linear reciprocal displacement along a guide rod 9 and therefore the entire image of the object 3 is scanned into said image sensor 6.
Referring to FIG. 2, when the image scanner is in the mode of scanning a transparent object, another glass plate 7 and said glass plate 2 are used to hold transparent object 8 (such as transparency, celluloid, etc.) in position on the scanning plane, and then lighting unit 4b, located above said transparent object 8, projects light through said transparent object 8. Said mirror unit 5 then reflects light from said transparent object 8 into said image sensor 6 as lighting unit 4b, mirror unit 5 and image sensor 6 simultaneously move down the entire length of transparent object 8.
The said conventional image scanner for scanning reflective and transparent objects, because the direction of the light is different for the two modes of scanning, must have two lighting units located in different positions, and two drive systems to drive image sensing unit for scanning in different modes. As a result the structure of said conventional image scanner is complicated and cost is increased. In addition, for scanning transparent objects, because lighting unit 4b, mirror unit 5 and image sensor 6 are driven by different drivers which must be synchronized, the controller is so complicated as to further increase its production cost.
In view of this, the inventor has devoted himself to thinking and research and finally developed the present invention through persistent testing and improvement based on experience in the production of related products over the years.